LB-002 - ASSOCIATION BETWEEN TREATMENT FOR MULTIPLE SCLEROSIS IN PREGNANCY AND PRECONCPETION PERIODS AND FETAL OUTCOMES - A REAL-WORLD RETROSPECTIVE COHORT STUDY

N. Gronich¹, N. Stein²; ¹Faculty of Medicine - Technion - Israel Institute of Technology; Clalit Health Services, Haifa, Israel, ²Lady Davis Carmel Medical Center, Haifa, Israel.

Background: Multiple sclerosis (MS), an autoimmune condition affecting the central nervous system and a leading cause of neurological disability, preferentially affects young females, potentially impacting a woman’s reproductive years. MS does not negatively influence most pregnancy outcomes. However, while drug labels are typically restrictive and favor fetal safety over maternal safety, withdrawal of some treatments during pregnancy can result in a substantial risk of pregnancy-related relapse. Much more data are needed to provide guidance on how best to achieve MS stability in pregnancy, balanced with fetal and newborn safety. In this study we explored, in a population-based clinical database, if treatment for MS, including disease-modifying treatments (DMTs) and corticosteroids, in the preconception period and/or pregnancy is associated with congenital malformations, or neurodevelopment disorders, including autism.

Methods: A retrospective cohort, based on the database of Clalit Health Services (CHS), the largest health maintenance organization in Israel, was established from all children, born between 1.1.2010 and 1.9.2023, to mothers carrying a diagnosis of MS. Excluded were multiple gestation pregnancies, prior malignancy, exposure to another known teratogenic drug, chromosomal anomalies/genetic diseases. Association between exposure to any treatment, and to each treatment group, with congenital malformations, or neurodevelopment disorders were explored in a multivariable analysis.

Results: The cohort included 1446 children. Mean age of mothers was 31.8 (SD 4.8); similar between exposure groups. A quarter of the children were exposed to treatment for mothers' MS in preconception/fetal life. Exposure to monoclonal antibodies, to S1P receptor modulators, or to steroids, during six pre-conception months/pregnancy was associated with numerically higher percentage of congenital malformation that was not statistically significant. There was no association between exposure to any treatment and neurodevelopmental disorders.

Conclusion: Most pregnant women diagnosed with MS are not treated during the preconception and pregnancy period. There was no association between exposure to DMT or corticosteroids and major congenital malformations or neurodevelopment disorders.